Well my friend, you have seen my zoos so there is no doubt that I will generally start all of my standard small zoos at the highest game default of $500,000. However, if I'm building on one of my own maps there is a lot more starting money because I'll use the cheat to set up a good starting fund to make the map itself.
The gate admission fee stays at the default of $22 when I first open the zoo. As more guests begin to arrive (and the GH starts to go down because of it) I'll raise the admission price by $2. Usually by the time I've completed a small zoo the price may range between $28 and $30.
Buildings: that depends on the building sometimes. Some of the restaurants will have the default price raised, while those that are user made may have the price lowered because I think it might be too high. Some of the food stands will have their prices raised by at least 50 cents in order to make a profit more quickly, such as the drink stand, hot dog stand and ice cream stand.
The one thing I have never done is mess around with the games' .ini file...with my luck I'd blow out the programming and would have to do my unistall/reinstall bit again :crash:
I hope this will be helpful to you.